Edit: I see — I think you mean exporting lowered StableHLO code in a shape polymorphic format —- from the docs: https://jax.readthedocs.io/en/latest/export/shape_poly.html
This is not the thing I usually think when someone says dynamic shape support.
In this model, you have to construct a static graph initially —- then you’re allowed to specify a restricted set of input shapes to be symbolic, to avoid the cost of lowering — but you’ll still incur the cost of compilation for any new shapes which the graph hasn’t been specialized for (because those shapes affect the array memory layouts, which XLA needs to know to be aggressive)